Powder distribution system for three-dimensional printer
The present invention relates to powder-layer three-dimensional printers ( 2 ) having a discrete supply hopper ( 340 ) and a recoater ( 20 ). The discrete supply hopper ( 340 ) is configured to transfer a build powder to the recoater ( 20 ) in a manner that enhances the uniformity of build powder layers that are dispensed from the recoater ( 20 ). In some embodiments, at least one of the discrete supply hopper and the powder hopper of the recoater is adapted to selectively contact the other, seal against the other, and/or have one partially inserted inside the other so as to diminish or prevent powder pluming during the transfer of build powder from the discrete supply hopper to the recoater.
1 . A powder-layer three-dimensional printer ( 2 ) comprising:
a recoater ( 20 ) and a build material discrete supply hopper ( 340 ), the discrete powder hopper ( 340 ) having
(a) a build powder reservoir ( 342 ) having a bottom opening ( 355 );
(b) a planar mesh ( 352 ), the planar mesh ( 352 ) being selectively permeable to a build powder and being located so as to permeably close off the bottom opening ( 355 ); and
(c) a selectively operable vibrator ( 362 , 364 ) in vibrational communication with the planar mesh ( 352 ) and/or the build powder;
wherein at least one of the recoater ( 20 ) and the discrete supply hopper ( 340 ) is adapted to vertically align the recoater ( 20 ) below the discrete supply hopper ( 340 ) for the build powder dispensed by the planar mesh ( 352 ) during the operation of the vibrator ( 362 , 364 ) to be received by the recoater ( 20 ).
2 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the recoater ( 20 ) has
(a) a sheet screen ( 28 ) having a plurality of perforations ( 126 ) and a first side and a second side;
(b) a first ultrasonic transducer ( 30 ) in vibrational communication with the sheet screen ( 28 ); and
(c) a build powder supply hopper ( 26 ) adapted to provide the build powder to the first side of the sheet screen ( 28 ); wherein when the first ultrasonic transducer ( 30 ) vibrates the sheet screen ( 28 ) the build powder from the build powder supply hopper ( 26 ) is dispensed from the sheet screen second side via the perforations ( 126 ).
3 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the vibrator ( 362 , 364 ) of the discrete supply hopper ( 340 ) comprises at least one of a second ultrasonic transducer ( 362 ) and a low frequency vibrator ( 364 ).
4 . The powder-layer three-dimensional printer ( 2 ) of claim 3 wherein the second ultrasonic transducer ( 362 ) is adapted to sweep across a frequency range during its operation.
5 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the discrete supply hopper ( 340 ) is movably located within the powder-layer three-dimensional printer ( 2 ).
6 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the planar mesh ( 352 ) comprises a wire mesh.
7 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the planar mesh ( 352 ) comprises a metal sheet having a plurality of perforations.
8 . The powder-layer three-dimensional printer ( 2 ) of claim 7 wherein the plurality of perforations include a first perforation having a first shape and a second perforation having a second shape wherein the first shape is different from the second shape.
9 . The powder-layer three-dimensional printer ( 2 ) of claim 7 wherein at least one of the size, shape, and distribution of the perforations of the plurality is varied to reduce any tendency the planar mesh ( 352 ) otherwise would have to dispense build powder non-uniformly due to local vibration variances.
10 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the build powder reservoir ( 342 ) is adapted to provide mass flow of the build powder to the planar mesh ( 352 ).
11 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the planar mesh ( 352 ) is mounted in a holder ( 354 ).
12 . The powder-layer three-dimensional printer ( 2 ) of claim 11 wherein the planar mesh ( 352 ) is bonded to the holder ( 354 ) by an adhesive.
13 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the discrete supply hopper ( 340 ) further comprises a selectively operable gate ( 356 ) located below the planar mesh ( 352 ).
14 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the discrete supply hopper ( 340 ) further comprises a cyclonic receiver ( 348 ) located above the build powder reservoir ( 342 ).
15 . The powder-layer three-dimensional printer ( 2 ) of claim 14 wherein the discrete supply hopper ( 340 ) further comprises a valve ( 350 ) interposed between the cyclonic receiver ( 348 ) and the build powder reservoir ( 342 ).
16 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the recoater ( 20 ) has a powder receiving area ( 372 ) and the planar mesh ( 352 ) has a powder discharge portion ( 370 ), the powder discharge portion ( 370 ) having a center which is vertically aligned with the powder receiving area ( 372 ) during transfer of the build powder from the discrete supply hopper ( 340 ) to the recoater ( 20 ).
17 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the planar mesh ( 352 ) has a powder discharge portion ( 370 ), the powder discharge portion ( 370 ) having at least one of the geometric shape and dimensions of a powder receiving area ( 372 ) of the recoater ( 20 ).
18 . The powder-layer three-dimensional printer ( 2 ) of claim 17 wherein the powder discharge portion ( 370 ) of the planar mesh ( 352 ) has a span (S 1 ) and a width (Wi) and at least one of the span (S 1 ) and width (W 1 ) is the same as the width (W 2 ) of the powder receiving area.
19 . The powder-layer three-dimensional printer ( 2 ) of claim 1 wherein the recoater ( 20 ) has
(a) a wire mesh screen ( 366 ) having a first side and a second side;
(b) a third ultrasonic transducer ( 367 ) in vibrational communication with the wire mesh screen ( 366 ); and
(c) a hopper ( 365 ) adapted to provide the build powder to a first side of the wire mesh screen ( 366 );
wherein when the third ultrasonic transducer ( 367 ) vibrates the wire mesh screen ( 366 ) the build powder from the hopper ( 365 ) is dispensed from the wire mesh screen second side.